Apparatus for converting hydrocarbon oils



Feb. l, 1944. R. LlDov API'ARATUS FOR CONVERTING HYDROCRBON OILS Filed April 30, 1940 o lll'. V v Sb t@ 0 m w E Qu ml f m o A nl? w E l m .KRNMWM N .wk E n u O h 1Q. i. l

Patented Feb. 1, 1944 OFFICE APPARATUS FOR CONVERTI'NG HYDRO- CARBON OILS Rex E. Lidov, Portland, Oreg. Application April 30, 1940, Serial No. 332,432

11 Claims.

This invention relates to an apparatus for converting hydrocarbon oils and more particularly to a system for converting ,hydrocarbons in the gasoline and gas oil boiling ranges into gases containing large proportions of oleiines and liquids in the motor fuel boiling range having a high octane number and a high octane blending value.

An object of the invention is to provide a commercially practical system of the type above indicated.

Another object is to provide a catalytic conversion system of the above type having novel and improved combinations of elements.

Another object is to provide an apparatus for vforming and separating the olefinic gases and the liquid motor fuel fraction.

Another object is to provide a novel and improved system for reactivating the catalyst in a catalytic converter of the type having a plurality of banks of catalyst tubes.

Various other objects and advantages will bevv apparent as the nature of the invention is more fully disclosed.

The present system, with suitable changes -in operating conditions, is adapted to converthydrocarbon charging stocks of various characteristics such as, for example, a gasoline fraction or a gas oil fraction from crude petroleum or recycle stock, or topped crude, into products containing hydrocarbon gases, gaseous olenes and a liquid fraction in the motor fuel boiling range, rich in the aromatics benzol, toluol and xylol, from which these aromatica may be separately obtained, or which in its entirety may be used as a motor fuel or as a motor fuel blending agent, or containing aliquid fraction in' the motor fuel boiling range chiey distinguished by its high octane and octane blending numbers and useful as a motor fuel or a. motor fuel blending agent.

In accordance with the present invention, the

charging stock is rst heated to a temperature to completely vaporize the same under conditions such that substantially no cracking takes place. If the nature of the charging stock is such that it cannot be completely vaporized under these conditions, the material may be passed to a flash chamber and separator for removing the nonvaporizable portion. The vapors only are then passed into the conversion zone wherein they are contacted with a suitable catalyst under conditions of temperature, pressure and space velocity r which favor the formation of the desired products.

The conversion zone, in one embodiment, comprises a plurality of tubes containing a catalyst, which are externally heated by suitable means to supply the necessary heat for raising the vapors to the desired outlet temperature.

The portion of the charge converted to gases is generally dependent upon temperature, a greater gas yield being obtained at higher temperatures. The gas yield is also related to the space mass velocity-and the pressure in the converter unit,decreasing as the space mass velocity increases, and to a lesser extent, decreasing as the pressure increases. The gas composition ir: gen,- eral is but little affected by temperature or space mass velocity, but the liquid composition is affected, the liquid becoming less aromatic with increasing space mass velocity and decreasing temperature.

inasmuch as the reactions are essentially in the vapor phase, when the feed to the converter system is constant the pressure affects both the space mass velocity and the related factor, the contact time of hydrocarbon vapors with the catalyst in the conversion zone. Aside from the changes exerted by pressure because of its effect on the contact time, it exerts an independent efllect on the nature of the products as a result of the changes it induces in the equilibria of the reactions in the vconversion zone. In general, the yield of olenes and particularly the yield of ethylene, decreases as the pressure increases and to a very much lesser extent the liquids tend to become more aromatic. It is obvious, of course. that the effect of changes in pressure on the contact time and the resultant elfect on the products can be eliminated by a proper selection of iiow rate or by other methods which will be made clear hereinafter. Consequently, by suitable control of these iactors, among others, it is possible to vary, within limits, the proportion of fuel gases, gaseous olefines, motor fuel and aromatics in the final product.

The vapors leaving the conversion zone are lmmediately cooled to a temperature suited to stop the reactions, which. may involve conversion or cracking or both. before the formation of undesired products takes place. In one embodiment of the present invention this is accomplished by introducing into the' vaporl stream a quench oil which is derived from a later stage foi the process. The'quench oil is preferably of such a nature that it .does not crack `or coke under the conditions to which itis subjected, leaves no residue and introduces no undesirable constituents which require additional steps or apparatus for their subsequent removal.

The vapor stream, after quenching, contains the desired products and the hydrocarbon used for quenching and may be treated in a suitable manner for the removal of the higher boiling residues and the subsequent separation of the gaseous olenes, the fuel gases and the motor fuel fraction. The olefines may be further separated into their components such, for example, as ethylene, propylene and butylene if desired. The liquid boiling in the motor fuel range may consist essentially of benzol, toluo1 and xylol and in its entirety will possess a high octaine number and high octane blending number which renders it suitable with but little subsequent treatment for use directly as a motor fuel or as a blending agent for increasing the octane number of other motor fuel. It may also be used as a source for the production of the aromatics benzol, toluol and xylol in pure form. The liquid fraction, depending on the operating conditions above mentioned, may have a smaller proportion of the aforesaid aromatics but will, in any event, be characterized by high octane and high octane blending values which render it, after but little subsequent treatment, suitable for use as a motor fuel oras a blending agent for increasing the octane number of other motor fuel.

Although the novel features which are believed to be characteristic of this invention are more particularly pointed out in the claims appended hereto, the invention itself may be better understood by referring to the following description, taken in connection with the accompanying drawing, in which a specific embodiment thereof has been set forth for purposes of illustration. A

In the drawing, the gure represents diagrammatically a converter plant embodying the present invention.

Referring to the drawing more in detail, the charging stock is supplied through a line I0, control valve II, pump I2 and heat exchanger I4 to a vaporizer coil I5. In the embodiment shown, this vaporizer coil comprises a bank of tubes I8 in a converter furnace 20. The furnace 20 may have a combustion chamber andA a convection zone arranged in any convenient manner. Inasmuch as the furnace may be of any standard construction, the various details of construction have not been set forth herein. It is to be understood that the tubes I6 may be located in the convection zone to be heated by the combustion gases prior to their removal from the furnace through a duct 2| to a stack 22.

The charging stock may be heated inthe convection bank I to a temperature such that cornplete vaporization takes place. It is to be understood, however, that vii.' the nature of the charge is such that complete vaporization without cracking cannot be obtained in the vaporizer coil, the unvaporized portion of the charge may be removed by suitable separating apparatus, not shown. The heat exchanger I4 serves to preheat the charge prior to passage to the vaporizer coil. It may, however, be omitted if desired.

The vapors from the vaporizer coil I5 are passed through a line 25 to a plurality of supply headers 28, the flow of vapors to each header being controlled by an individual valve 21. To each header 26 is connected a bank of conversion tubes 28 whichare located in the furnace 20 in a position to be heated therein to a high temperature. They may, for example, be located in the radiant heat zone of the furnace. The tubes 28 of each bank are connected to an outlet header 29 and thence through individual lines 30 controlled by valves 3| to line 32. The tubes 28 may be arranged vertically or horizontally and it is to be understood that the number of banks may be increased or decreased as desired. Four banks of vertical tubes have been shown merely for purposes of illustration. It is also to be understood that the furnace is fired by suitable burners, not shown. A bypass 25a having a valve 25h is connected between the lines 25 and 32 to permit the converter tubes 28 to be bypassed during warming up periods before complete vaporization takes place in the vaporizer coil I5.

The line 32 is connected through heat exchangers 33 and a condenser 34 to a separator 35. The gases from the top of the separator. which consist of the fixed gases, such as hydrogen, methane, ethane and the gaseous oleflnes. such as ethylene, propylene and butylene, may be taken by a line 35 to a suitable gas separation unit.

The liquid from the separator 35 which contains the aromatic fraction and a high percentage of dissolved gases, is taken through a pump 4I) and line 4I to the heat exchangers 33 wherein it is reheated to a desired temperature, and thence through a line 42 to a fractionating co1- umn 43. The temperature to which the liquid is reheated in the exchangers 33 may be controlled by a bypass 4Ia and valve 4Ib.

The overhead from the fractionating column which contains the aromatic fraction as well as the oleiine gases which have not been removed in the separator 35 is taken by a line 44 through a condenser 45 to a separator 46 wherein the gases are removed andare passed through a line 41 to the line 3B wherein they join the gasesfrom the separator 35 and are supplied to the gas separation unit, not shown. The liquid fraction from the separator 46 may be taken through a line 48 and pump 49 to a suitable treating unit, not shown, for conditioning the same for use as a motor fuel or as a motor fuel blending agent. A portion of the liquid from the receiver 46 may be recycled by a pump 50 through a line 5I to the top of the column 43 for temperature control purposes.

The residue from the bottom of the fractionating column 43, which may comprise a heavy fuel oil, may be passed by a pump through a. cooler 56 and a line 51 to storage.

A side cut may be taken from the fractionating column 43 by means of a line 60 to a side cut stripper 6I ofany standard type. The vapors from this side cut stripper may be returned to the column through a line 62. Steam for stripping the fraction may be supplied by a line 53. The liquid, which may comprise a gas oil fraction, may be taken through a line to the heat exchanger I4 and may be supplied by a pump 66 and a set of branch lines 51, controlled by valves 68, to suitable injectors in the outlet headers 29 wherein it is mixed with the vapors from the tubes 28 and serves to quickly cool or quench the same to a predetermined temperature suited to stop the conversion reaction. Any excess of the side cut over that required for quenching purposes may be taken through a line 69 controlled by a valve 10 to storage or for use as fuel oil, or may be recycled as charging stock for the process by means of a pump 1I and a line 12 controlled by a valve 13. The recycle stock may be removed either before or after it passes through the heat exchanger I4.

Air and steam for reactivating the catalyst in the tubes 28 may be supplied from a steam line and an air line 16, controlled by valves 11 and 18 respectively through a line 80 to a coil 85 which may constitute a preheater or superheater coil in the furnace 20, thence through a line 86 and branch lines 8l controlled by valves 82 to the supply headers 28. The outlet headers 28 may be connected through valves 88 to a blow down line 84. Steam may also be introduced by line 88 through individual valves 89 into the lines 81 so as to prevent overheating of the outlet headers during the reactivation periods.

When a bank of converter tubes is to be cleaned or reactivated, the corresponding valves 21, 8i and 88 are closed to remove thebank from the vapor stream and to interrupt the supply of quench oil thereto. By opening the valves 82 and 83 associated with the bank to be reactivated and by suitable control of the valves 11 and 18, air and steam may be supplied to the tubes from the lines 'l5 and 16 in regulated quantities as required for reactivation purposes and the reactivation products may be removed through the blow down line 84.

In carrying out the present process for the conversion of a charging stock Within the gasoline boiling range (100 F. to 380 F.) or a charging stock such as gas oil (380 F. to '750 F.) which contains no non-volatile reject, the charge may be heated in the vaporizer coil l5 to a temperature of 650 F. to 850 F. at a suitable pressure to cause the desired rate of gas flow through the remaining apparatus, such, for example, as a pressure up to 50 lbs., the particular temperature and pressure conditions being selected so that no substantial cracking will take place prior to the conversion step. ln the event that the crude contains a fraction which cannot be vaporized without cracking at the above temperatures, the latter is removed by passing the vapors through a suitable flash chamber or other suitable separating means, not shown.

The vapors from the vaporizer coil or from the flash chamber are passed directly into the conversion unit where they are contacted with the catalyst in the tubes 28 under conditions of temperature, pressure and space velocity adapted to favor the formation of the desired product. It has been found that with 21/2 tubes 15 feet long, with an outlet temperature of between 1150 and 1500" F. and at pressures between sub-atmospheric and about lbs. per sq. in., the flow rate or space mass velocity may vary from 1 to 10 units, a unit being defined as the velocity required to pass 62.4 lbs. of oil per hour per cu. ft. of catalyst space. This velocity may, for ex ample, result in a time of contact with the catalyst of from 0.2 to 3.0 seconds, depending upon the porosity of the catalyst and the percentage of free space in the tubes.

It will be readily apparent that some finite time will be required to bring the oil vapors in the conversion zone from the temperature of approximately 850 F. at which they enter, to a final temperature within the limits of 1150-1500 F. The vapors may be made to attain a temperature in excess of the desired final temperature in their passage through the first 1015% of the conversion zone but a point is then reached at which an extremely rapid drop in the vapor temperature takes place, to a temperature Well below the desired final outlet temperature, despite the fact that heat in large quantities is constantly supplied to the conversion zone. Following this es an rapid drop, the vapor temperature then rises to the desired final temperature and the vapors can then be made to complete their passage through the conversion zone at temperatures within 50 F. plus or minus of the desirable final outlet temperatures. The period of rapid temperature drop is normally completed by the time the vapors have travelled through the first 40% of the conversion zone. It is likely that the zone in which the fall in vapor temperature occurs represents that zone in which gasification takes place most rapidly with consequent rapid absorption of the endothermic reaction heat by the vapors. It is possible, by controlling the rate of heat input at various parts of the conversion zone, to flx the peak temperature attained by the vapors before the point of rapid temperature drop is reached, and also to fix the shape of the temperature curve in the last 60% of the conversion zone.

In its preferred embodiment the present system should be provided with a means for heat input into the conversion zone of such a type that a temperature well in excess of the desired final temperature is attained before the point of rapid temperature drop is reached, and such that, following the temperature drop, the vapors again rise to the desired outlet temperature as rapidly as possible and remain at that temperature for the balance of the time they are in the conversion zone. However, the present invention is not intended to be limited to use with such heat input, but for ease of practical design the temperature gradient may be varied as desired to produce the optimum average temperature.

An important feature of the present invention resides in the elimination of the necessity for careful control of temperatures along the conversion zone, it being required only that the vapors be passed through the zone under conditions of contact time and pressure herein disclosed, and made to attain by the end of the passage a temperature in the range 11501500 F., in accordance with the products desired.

It should be further understood that any limiting control tending to maintain the vapor temperature below the final temperature in the first half of the conversion zone is not ordinarily desirable.

The percentage of olefines and the relative proportion of the different olefines is influenced by the selection of the catalyst as well as by the other factors above mentioned. The catalysts selected will accordingly depend upon the product desired. It is to be understood that the term catalyst" is used in a broadr sense and is not intended as a definition of the action of the material. The material may act as a true chemical catalyst to promote the reaction or may act mechanically by surface contact or in various other ways. It has been found that the presence of certain substances favors the formation of certain products and these substances are herein, for convenience, called catalysts.

Various known catalysts may be used in the present system, such as'difiicultly reducible metal oxides in active form, preferably supported on a suitable carrier such as silicon carbide; metals in such form as to be catalytically inert for the decomposition of hydrocarbons to carbon and hydrogen, etc. Certain catalysts which I have found to be particularly suited for this system are disclosed and claimed in my copending application, Ser. No. 327,470 filed April 2, 1940. The present invention, however, is not restricted to the use of such preferred catalysts as other known catalysts may be used with suitable selection oi operating conditions to obtain the desired result.

The tubes are lled with the selected material of the size of grain to be used will depend upon a number of factors, among which may be mentioned the length and diameter of the catalyst bed, the rate o1' iiow to be employed and the per- !nissible pressure drop through the catalyst bed, the latter having an effect upon the total pressure in the system and consequently. as elsewhere explained, on the nature of the products obtained. The tubes themselves should be made of a material which does not interfere with the catalytic cracking of the vapors therein and which does not, itself, catalytically direct the cracking into undesirable directions. Tubes comprising an alloy 18% chromium, 8% nickel, and the remainder for the most part iron have 'been found to be satisfactory, but it is not intended that the invention is limited to use with such tubes.

v suitable separation unit.

The quench oil is introduced into the outlet headers to cool the vapors below the reaction temperature as soon as the desired reaction has taken place. With an oil of the above type, the vapors should be cooled to a temperature of from 650 F. to 750 F. In the embodiment shown in the drawing this is accomplished by injecting a quench oil into the outlet headers 29. It is to be understood, however, that this is merely for purposes of illustration and that the oil may be introduced at other points and in other ways or the vapors may be bubbled through an oil bath. In any event, the arrangement is such that the vapors are cooled rapidly before undesirable reactions take place.

In the embodiment shown, the quench oil comprises a side cut taken from the fractionating column 43. This side cut may constitute a fraction within the gas oil boiling range which, having already been subjected to conversion conditions, will not, under the conditions prevailing in the quenching zone,redily further crack or coke, which vaporizes at the temperature of the vapor stream without leaving a residue and which introduces no undesirable constituents which require special steps or apparatus'for their subsequent removal. It is to be understood, of course, that other quench oils may be employed if desired In any particular instance. The quench oil is shown as coole'd by heat interchange with the The gases will contain the desired olefines such as etlnrlene, propylene and butylene, and the fuel lgases such as hydrogen, methane. and ethane. together with minor amounts of liquid hydrocarbons having high vapor pressures. such as amylene, benzol, hexylene, etc., which may be present as unseparated vapors, These various constituents may be separated by any suitable means not shown. The liquid fraction may be treated to condition it for. use as a motor fuel or as a blending agent for improving the octane number of other motor fuels or when it is produced under conditions which make it highly aromatic, it may be treated to separate therefrom the aromatics such as benzol, toluol and xylol,

and other materials or mixtures of materials suitable for various purposes.

In operating thissystem, it has been found that periodic regeneration of the catalyst is required. probably because of carbon deposition thereon. The converter tubes are accordingly arranged so that one of the banks may be removed from the stream and regenerated while the process is continued with the remaining banks. In regenerating the catalyst, after the converter tubes have been removed from the stream they are prefer ably rst blown with dry steam to remove any residual vapors and to prevent the formation of explosive mixtures therein.

charging stock for purposes of heat conservation.

The vapors in the line 32 leaving the converter furnace contain the gaseous olenes, fuel gas, a minor amount of other permanent gases, the motor fuel fraction and heavier residues. They are cooled in the heat exchangers 33 and the condenser 34 to make a primary separation of the permanent gases in the separator 35. 'I'he condensate in the separator 35 which contains the motor fuel fraction and the heavier residues, as well as a substantial quantity of entrained gases, is pumped through the line 4I to the fractionating column 43 which is operated under suitable conditions of temperature and pressure to separate the residue which is withdrawn from the bottom as a heavy fuel oil. |Ihe overhead vapors containing the motorfuel fraction and entrained gases are then condensed in the con- Thereafter, a suitable mixture of dry steam and air may be supplied to burn out the carbon,

the quantity of air being controlled so as to avoid an excessive rate of combustion. The tubes may or may not be removed from heat transfer relationship with the furnace during this part of the process. vlifter the carbon has been completely burned out, the tubes may again be blown with dry steam to remove residual air before being returned to stream.

The air or ythe air and steam mixture may be preheated or the steam mixtures may be super'- heated in the coil 85 so as to tubes to below reaction temperatures during reactivation and also to prevent introduction of moisture into the system or into contact with the hot catalyst, which might result in tube ruptures.

By the use of four banks of catalyst tubes, it will be noted that three banks are always on stream, that is, three-fourths of the converter capacity is always in productive use. Obviously, if the number of banks is increased the relative proportion of banks in productive use will be increased. lonr banks have been shown merely i'or purposes of illustration. This system of catalyst abOut 400 version process in which the ow of products is not interrupted or greatly disturbed during reactivation periods.

In a specific embodiment of the -invention utilizing Michigan gas oil of about 39 gravity and operating to favor the production of ethylene, the charging stock may be supplied by the pump I2 at a pressure of 100 lbs. to the heat exchanger I4 wherein it may be raised to a temperature of F. 'I'he stock may be further heated in the vaporizer coil I5 to a temperature of about 800 F. and may be supplied to the converter tubes 28 at a pressure of about 35 lbs. per sq. inch. The vapors may be heated In the converter tubes 28 to an outlet temperature of 1400" F. and

immediately quenched in the outlet headers 29 prevent cooling the fuel gas and a liquid fraction in the motor fuel y boiling range having a high octane number and a high octane blending value. which comprises a vconverter furnace having at least one bank comprising a plurality of externally heated converter tubes terminating in a common outlet header, a vaporlzer coil disposed in said furnace, means for supplying a hydrocarbon charging stock to said coil, means for heating said stock therein to a vaporizing temperature, means for supplying vapors from said vaporizing coil to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of the above mentioned products, means for injecting into the vapors in said outlet header, after conversion, a quench oil suited to cool the vapors to a temperature suiiiciently low to stop the conversion reaction, a fractionating column, means for supplying the conversion products thereto, means for withdrawing the oleflnic and motor fuel fractions as a vapor from the top of said column and means for separating the olefines from said motor fuel fraction.

2. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous oleiines, the balance being fuel gas and aliquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value. which comprises a converter furnace having at least one bank cornprising a plurality of externally heated converter tubes terminating in a commonoutlet header, a vaporizer coil disposed in said furnace, means for supplying a hydrocarbon charging stock to said coil, means for heating said stock therein to a vaporizing temperature. means for supplying vapors from said vanorizing coil to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of the above mentioned products, means for injecting into the vapors in said outlet header.

after conversion. a quench oil suited to cool the vapors to a temperature sufficiently low to stop the conversion reaction. a fractionating column, means for supplying the conversion products thereto, means. for withdrawing the olefinic and motor fuel fractions as a vapor from 'the top of said column. means for separating the oleiines from said motor fuel fraction, means for withdrawing a side cut from said fractionating co1- umn, and means to supply the same for use as the quench oil above mentioned.

3. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous oleiines, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high ,octane blending value which comprises a converter furnace having an externally heated vaporizer coil and converter tubes arranged in banks, an outlet header connected to receive vapors from the tubes of each bank, means for supplying a charging stock to said coil, means for heating said stock therein to a vaporizing temperature, means for supplying vapors from said heating means to said converter tubes for heating therein to a conversion temperature suited to the formation of the above mentioned products, means to inject a quench oil into said headers to cool the vapors therein to a temperature suiiiciently low to stop the conversion reaction, and separating means to separate the olenic and motor fuel fractions from the remaining reaction products.

4. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous oleflnes, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises a converter furnace having at least one bank comprising a plurality of externally heated converter tubes terminating in a common outlet header, a vaporizer coil disposed in said furnace, means for supplying a charging stock to said vaporizer coil, means for heating the charge therein to a vaporizing temperature, means for supplying the vapors to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of oleflnes and aromatics, means for withdrawing vapors from said converter tubes, means for injecting a quench oil into said vapors in said outlet header to cool the same to a temperature below an active conversion temperature, means for cooling said vapors to a temperature adapted to condense the liquid fraction, a separator connected to separate a portion of the permanent gases, including clefines, a fractionating column, means for reheating the condensate from said separator and supplying the same to said fractionating column, means for operating said fractionating column at a temperature to remove the remainder of the olenes and the motor fuel fraction overhead as a vapor and gas, and means for cooling the vapors to condense the motor fuel fraction and separate the same from said gas.

5. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous oleiines, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises a converter furnace having at least one bank comprising a plurality of externally heated converter tubes terminating in a commonloutlet header, a vaporizer coil disposed in said furnace, means for supplying a charging stock to said vaporizer coil, means for heating the charge therein to a vaporizing temperature, means for supplying the vapors to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of the above mentioned products, means for withdrawing vapors from said converter tubes, means for injecting a quench oil with said vapors in said outlet header to cool the same to a temperature below an active conversion temperature, means for cooling said vapors at atmospheric pressure to a temperature adapted to condense the liquid fraction, a separator connected to separate a portion of the pern marient gases, including olenes, a fractionating column, means for reheating the condensate from said separator and supplying the same to said fractionating column, means for operating said fractionating column at a temperature to remove the oleiinic and motor fuel fractions overhead as a vapor, and means for cooling the vapors at atmospheric pressure tc condense the motor fuel fraction.

6. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous olenes, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises a converter furnace having at least one bank comprising a plurality of externally heated converter tubes terminating in a common outlet header, means for supplying hydrocarbon vapors to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of the above mentioned products, means for injecting into the vapors in said outlet header a quench oil suited to cool the vapors to a temperature sufficiently low to stop the conversion reaction, and separating means to separate the olefinic and motor fuel fractions from the remaining reaction products.

7. The process for converting hydrocarbon oil charging stock into products containing a large proportion of gaseous olefines, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises supplying hydrocarbon vapors to a conversion zone 4comprising a plurality of parallel connected, externally heated paths terminating individually in a common transverse outlet path forming a header, heating the vapors in said conversion zone to a conversion temperature suited to the formation of the above mentioned products, injecting into the vapors in said outlet header a quench oil suited to cool the vapors to a temperature suinciently low to stop the conversion reaction, and separating the olenic and motor f uel fractions from the remaining reaction products- 8. The process for converting hydrocarbon oil charging stock into products containing a large proportion of gaseous olenes, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises supplying hydrocarbon vapors to a conversion zone comprising a plurality of parallel connected, externally heated paths terminating individually in a common transverse outlet path forming a header, heating the vapors in said conversion zone to a temperature between 1150o F. and 1500" F. and at an outlet pressure of not more than 50 pounds per square inch while passing the vapors through said zone at a velocity to maintain a contact time therein of between about 0.2 to 3.0 seconds to form the above mentioned products, injecting into the lvapors in said outlet header a quench oil suited to cool the vapors to a temperature between about 650 F. and 750 F. to stop the conversion reaction, and separating the olenic and motor fuel fractions from the remaining reaction products.

9. The process for converting hydrocarbon oil porizingv temperature, supplying vapors from said vaporizing zone to a conversion zone comprising a plurality of parallel connected, externallyv heated paths terminating individually in a common transverse outlet path forming a header, heating the vapors in said conversion zone to a conversion temperature suited to the formation of the above mentioned products, injecting into the vapors in said outlet header a quench oil suited to cool the vapors to a temperature sufficiently low to stop the conversion reaction, supplying theconversion products to a fractionating zone, Withdrawing the olefinic and motor fuel fractions as a vapor from the top of said fractionating zone, separating the oleflnes from said motor fuel fraction, withdrawing a side cut from said fractionating zone, and supplying the same for use as the quench oil above mentioned. 1

10. A system for converting hydrocarbon oils for the production of products containing large proportions of gaseous olefines, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises a converter furnace having at least one bank comprising a plurality of parallel connected, externally heated converter tubes containing a catalyst and terminating in a common outlet header. means for supplying hydrocarbon vapors to said converter tubes, means for heating the vapors therein to a conversion temperature suited to the formation of the above mentioned products, means for injecting into the vapors in said outlet header a quench oil suited to cool the vapors to a temperature sumciently low to stop the conversion reaction, and separating means to separate the olenic and motor fuel fractions from the remaining reaction products.

yi1. The process for converting hydrocarbon oil charging stock into products containing a large proportion of gaseous olefines, the balance being fuel gas and a liquid fraction in the motor fuel boiling range having a high octane number and a high octane blending value, which comprises lsupplying hydrocarbon vapors to a conversion zone comprising a plurality of parallel con nected, externally heated paths containing a catalyst and terminating individually in a common transverse outlet path forminga header, heating the vapors in said conversion zone to a conversion temperature suited to the formation of the above mentioned products, injecting into the vapors in said outlet header a quench oil suited to cool the vapors to a temperature sufficiently low to stop the conversion reaction, and separating the olenic and motor fuel fractions from the remaining reaction products. p

, REX E. LIDOV. 

